The invention relates to a pneumatically actuatable surgical instrument comprising a handle, a pressurized gas operated tool arranged at the handle, a replaceable pressurized gas reservoir and a locking device for fixing the pressurized gas reservoir on the handle in an operative position in which the pressurized gas reservoir is connected to a pressurized gas channel by which the tool is supplied with pressurized gas.
The pneumatically actuatable surgical instruments described at the outset often receive their supply of pressurized gas from pressurized gas reservoirs in the form of pressurized gas cartridges so that the need for connecting the instrument to a pressurized gas hose for its supply with pressurized gas can be dispensed with and maximum ease of handling of the surgical instrument is achieved.
A problem with the pneumatically operated instruments that are equipped with a pressurized gas reservoir is that when a pressurized gas reservoir has reached the end of its useful life, it always contains a residual volume of pressurized gas and this will escape with a loud explosive sound at the time of removing the pressurized gas reservoir from the instrument.
Pneumatically operated instruments constructed in accordance with the invention and comprising a pressurized gas reservoir are often employed in difficult interventions on the central nervous system. Examples of such instruments include pneumatically operated bone punches which permit the removal of bone or tissue material from a patient by applying a large force.
If the surgeon is still occupied with a difficult procedure and the replacement of a pressurized gas cartridge of a pneumatically operated instrument is going on in the background, the surgeon can easily be startled into uncontrollable reactions.
In pneumatically operated bone punches it is of particular importance for the punching force not to decline during the intervention on the patient because otherwise, in the intervention on the patient, the shaft may stay fixed at the bone, while on the other hand the force of the punch no longer suffices to cut through the bone material. Therefore, in this kind of pneumatically operated bone punches the function of the bone punch is automatically limited when pressure reaches or falls below a minimum value.
As a consequence of this, the pressurized gas reservoir has considerable amounts of pressurized gas left inside; here the remaining pressurized gas pressure is for example approximately 2 bar, which is a pressure sufficient to produce an explosive sound of varying degrees of loudness every time the pressurized gas reservoir is replaced.
On the other hand, if the pneumatically operated instrument and the pressurized gas reservoir arranged therein had not been made use of extensively during surgery, it may also be that at the end of surgery the pressurized gas reservoir is still almost full. However, to allow for further use, the instrument then must be reconditioned and this inevitably requires the pressurized gas cartridge to be removed. Here the pressure remaining in the pressurized gas reservoir is even much higher and here as well it is important that removing the pressurized gas reservoir poses no danger to the staff.